The invention is based on a controlling device as revealed hereinafter. In a controlling device of this kind, such as that known from the ASME-Publication No. 78-DGP-7 and German Offenlegungsschrift No. 24 02 374, an adjustable full-load fuel stop is proposed which limits the drag lever in adjusting direction of the excess fuel. This lever is, based on the initially referenced publication, also adjustable in interdependency with the charge-air pressure.
The known controlling device has the disadvantage that the drag lever effected by the high pressure of the governor spring layout exerts relatively high force on the adjustable stop. Thus, adjustment of the stop results in high friction causing distinct hysteresis behavior at full-load adjustment. This behavior proves even more disadvantageous during injection with a load-pressure dependent adjustment at the injection pump, since the adjustment errors are considerably amplified with an increase in rpm and load. The reason being, that charging characteristics and feed-pressure are dependent upon the load and are becoming more dependent with increased rpm and thus influence the adjustment characteristics set forth by the requirements of the combustion engine, thereby also resulting in a leveling off of adjustment quantity. For example, vibrations and natural oscillations transmitted to the injection pump at full-load operation and fuel regulation of the fuel of the full-load injection quantity occur much earlier resulting in a speed adjustment with insufficient fuel quantity. Massive acceleration and forces exerted by the governor spring on the full-load fuel stop cause the abutted parts to be affected and thus the oscillating amplitudes of these parts are increased, resulting in the simulation of a decreased fuel injection quantity.